Chair with tilting back and automatically shiftable seat



May 24, 1949. R. A. CRAMER 2,471,024 CHAIR WITH TILTING BACK ANDAUTOMATICALLY SHIFTABLE SEAT I Filed 001;. 4, 1946 5 Sheets-Sheet 1 I EI INVENTOR. J figz rAL [NAME/Q y 4, 1949. R. A. CRAMER T 2,471,024

7 CHAIR WITH TILTING BACK AND AUTOMATICALLY SHIFTABLE SEAT Filed Oct. 4,1946 I 5 Sheets-Sheet 2 mmvrm RMYA. [RAM ER May 24, 1949.

R. A. CRAMER CHAIR WITH TILTI NG BACK AND AUTOMATICALLY SHIFTABLE SEATFiled Oct. 4, 1946 3 Sheets-Sheet 3 will/Ill.-

INVENTOR.

Patented May 24, 1949 CHAIR WITH TILTIN G BACK AND AUTO- MATICALLYSHIFTABLE SEAT Roy A. Cramer, Kansas City, Mo.

Application October 4, 1946, Serial No. 701,320

19 Claims.

This invention relates to chairs and more particularly to improvementsin posture chairs of the general type having automatically tiltablebacks.

One of the objects of the present invention is to provide a novelposture chair construction which combines an automatically tiltable backand shiftable seat in such a manner that an exceedingly comfortableaction is achieved when the chair is in use.

A further object of the invention is to provide a chair of the abovetype wherein, as the back is tilted rearwardly, the seat automaticallymoves forwardly, thus securing an easy and natural pivotal action of theupper and lower portions of the users body substantially about the hipjoints.

Another object reside in th provision of a chair having a novelconstruction which insures that during tilting of the back, the seatwill automatically shift forwardly and the chair back will automaticallyfollow the movements of the users back, in order to eliminate alltendency toward objectionable back-rub.

A further object includes the novel feature of maintaining the correctbalance of the chair and its occupant with respect to the chair baseduring all angles of tilt of the chair back.

Still another object resides in providing a chair of the foregoingcharacter which includes in addition to the automatically tiltable backand shiftable seat, a construction which enables the seat to beinitially adjusted forwardly or rearwardly with respect to the chairsupport or pedestal and independently of the back, this arrangementproviding a ready adjustment to accommodate the chair to different sizepersons.

A still further object comprehends a novel chair construction includingrelatively few parts which are relatively simple in construction andwhich may be economically manufactured and assembled.

Other objects and features of the invention will appear more fullyhereinafter from a consideration of the following detailed descriptionwhen taken in connection with the accompanyin drawings wherein apreferred embodiment of the invention is illustrated. It is to beexpressly understood however that the drawings are employed for purposesof illustration only, and are not designed as a definition of the limitsof the invention, reference being had for this purpose to the appendedclaims.

In the drawings, wherein similar reference characters refer to similarparts throughout the several views;

Fig. 1 is a'side view, partly in section, of a chair constructed inaccordance with the present invention, and illustrating the normalposition of the back and seat;

Fig. 2 is a view similar to Fig. 1, showing the position of the partswhen the back is tilted and the seat shifted forwardly;

Fig. 3 is a plan view, Partly in section of the bottom of the seat andadjusting members associated therewith;

Fig. 4 is a partial sectional; view taken substantially along line 4--4of Fig.3;

Fig. 5 is a plan view of the bottom of the chair plate;

Fig. 6 is a transverse sectional view taken substantially along line 5-6of Fig. 5, and

Fig. 7 is a transverse sectional view taken substantially along line 1-1of Fig. 5.

Referring more particularly to Figs. 1 and 2, a chair constructed inaccordance with the principles of the present invention is illustratedtherein as comprising a'base orsupporting pedestal I0 having a seatspider I 2 secured to the upper end thereof, the said spider beingformed to support a cushioned seat It and a back I6, in a novel mannerwhich will appear more fully hereinafter. It will be understood that thepedestal I0 is adapted to be supported by any suitable type of base, thearrangement being such that the pedestal and hence the height of theseat, may be adjusted vertically, in a conventional manner.

One of the dominant features of the present invention, as illustrated inFigs. 1 and 2 resides in the novel construction and cooperation of theseat spider 12, the seat I 4 and the chair back I6, the arrangementbeing such that as the back It automatically tilts from the positionshown in Fig. 1 to the solid line position shown in Fig. 2, the seat Itautomatically shifts forwardly as illustratedin this latter figure. Inaddition to such forward shifting of the seat, it will be seen from Fig.2, that the rear portion of the seat shifts downwardly a slightdistance, this action being clear from an inspection of the normalposition of the seat and back, shown in dotted lines, and theautomatically adjusted position, shown in full lines, whichthe partsassume as the back is tilted rearwardly.

In use, the automatic movement of the parts, above referred .to, isachieved as the occupant presses the back 16 rearwardly with apredetermined efiort, the operation resulting is an exceedinglycomfortable action accompanied by the entire elimination of back rub. Ifdesired, the chair may be equipped with a pair of arm rests, one ofwhich is shown at l9, and preferably the arm rests are carried byportions 2! and Zia, Fig. 3, of the tiltable back Hi, this arrangementfurther increasing the comfortable action when the chair iisin use. .Itis'ialso preferred that the back 16 be prcvi'ded'wlth a cushioned backrest l8 which may automatically tilt about a horizontal axis in anysuitable manner, such as for example, as showniinfmyaapplication SerialNumber 690,498, filed August 1451946, for Chair back. The back rest may.also be adjustable vertically as by means of a'handwheel 20, in orderthat it may readily. be accommodated to the most comfortable positionwith relation to the back of the occupant.

In order to secure thesabove highly desirable results;-zandvreferringtbF-Eiis-fil and "4, "-the'-:back i6 is formed with an upstanding post:-l 1: for receiving thebacl-r rests, and allpair of: arms Y 22 and 24which are spositioned beneath :the seat l4 .and' extend forwardlynoneither side-of the pedestal Ill. As showni -the forwardextremities of'the arms 22 and 24,- are :pivotally connected, as byr-means of aeshaft2.6470 8. pair of forwardly extending arms 28 andr3ll==-iomied*integrally with the-spider J2.- WithJsuch an arrangement,it will beaneadilysperceivedmthatltheback IB- may be tilted in themanner illustrated in Fig- 2, the arms 22 -and ztpivotingmpon the: shaft26 and with respect .toethe' s'tationary. (arms 28 and 30 of the'spiderl2.

Novel means are provided by the invention for slidably mounting the:seat L4 .uponthe seatsupport including the' spider l2, and .one iofLtheimportant features "resides in associating the seat with'th'e' tilting"were 3l6iine'such manner as to secure the automatic forward'sl'iiftin'g'of the seat as the back :16 tiltsitotheposition illustratedin full llnes..inFig."-'2l A'sfsh'o'wn', such means includes'a'.,'.chann'el shaped adjusting member 32 havinga'paii' 'of spacedapartplates' 34 and 36 connected bya base'fportior'ii38, the .saidplates beingfipivotal'ly"connected to'rearwardly' extending arm's ljll-an'd "l2 ofith'e Spider 1'2, as by. means of a "shaft "44. :Irr'amanner to. be'mcre'particularly referred to% hereinafter, the seat 'll'is'supportedupon a plate 18* havinghpair 'ofde'pending brackets beans*fifl'secure'd -thereto, thelatter being'pivotally connected tothe'plates 34 and "36 as by'meansof' aw-rod 52 positioned above-and insubstantial vertical alignment with-theshaft '44.The-"forwardportions"of"each"of the plates '34 and 36-a're respectively'p'rbvidewwith cam'slots 54;'-one of which is""shown'- Fig: '4, 'and"within these slotsycam rdilfsbfi and are positioned, the latterbeing'carried by arrhs' H-and "24 of the back- -l6=in'-'any suitablemannergsuch'as by means ofstdb shafts'60: From' thisarrangement, it willice-readily '-seen'= that 'a'sthe"back I 6-is' tilted; and the arms 22ar'id -24"pivot*downwardly about the shaft 2'6',*the cooperatiori'betweenthe cam rollers 56 and "58'and' theslot ilwill cause'theadjusting member 32 to pivot inaclookwise direction "about the-shaft M2-Su'chpiviotal' action 'of'member 32 causes the brackets 48"an-d50;?plaite and seat [4 to *shiitdownwardly*andforwardly as "heretoforepointed-out in-connectionwith Fig. 2. such'shiftingo'f-"the"se'at;"relative tathespider I 2; isreadily enabled by-providingthe plate 46 with 'a' pair ofidepending "guide" channels 62, 64 whichare positioned 'to'receive and guide rollers 4 66 and 68 respectively,carried by the ends of shaft 26.

In order to maintain the parts in the position shown in Figs. 1, 3 and4, and to yieldingly resist the back-tilting and seat-shiftingmovements, the present invention provides a pair of expanding springsand 12 which are interposed between the base 33 of the adjusting member32 and a crossehead I4 oper atively connected with the seat spider I2.More particularly, each of the springs in and 12 is provided with aninternal support including a rod and sleeve construction 16,- Whilean'a'djustment of the tension of springs ill and 1.2 is secured by anadjusting wheel 13 having a part 80 threadedly engaging a brace 82formed integrally with the arms 28 and of the spider. As th'ehand wheeli8 is adjusted to move the cross-head 14 toward the brace 82, thetension oi the springs 10 and I2 is increased and hence the forcerequired to tilt the back l6 and shift the seat Ml is likewisedncreasedThus, desirablevariations in-"spri'ngtension may :becreadily secured byasimple adjustment, readilyaccessible at the forward part of the chair.

Means are provided to limit-the return-movement of the seat, when theback 'I G returns to the normal uprightposition, 1 and preferably suchmeans -is so arranged as to be shock absorbing in character; Asshown,:suchmeansiincludes stop flanges 84 and 8B, respectivelyz tormed'on the guide channels Bland 64, at-bl'ock :of'rubber 38 being preferablysecured to the rearr'faces 'of'the flanges to engage the forward trendsof the'asarms 22 "and '24 lastheseattisamoved rearwardly and-returnedtonorm'alposition.

In addition to the foregoing novel features, the present invention alsoprovides arconstruction whereby the horizontal position'of't-he'seatwith respect to its 'supportingz-basean-d the'zback, may

be varied in' order to iwiden 'orrnarrowithe seat depthtosuitthezpa-rticular-zuserzi In the form of the inventionillustrated;seerFigs; 5; -6 and 7., such construction-includes an adjustable handscrew 90, which when adjusted-is-capableof-moving the seat 14 forwardlyor rearwardlywith-v respect to the plate 46.

-Moi'-e-particularly, theseat 14 includes a-seat plate 92*havingapair ofspaced apart guide rails 94 and 96 secured theretoandengagin-gthe'topadjacent opposite edges 'of the-plate 46. Spacer strips 98 and [00 are:secured tozthe rails '94 and 96 respectively, and asshown in Figs.- Band7, additional guide rails li-fll-and I04 are respectively secured tothe-strips 98 .andl-00.-over .a substantial part oi'the-rear portions ofthe strips to form enclosed guides fQrM sIidablyHsecuring "the. seatp1ate.92 to the plate '46. .A. bracket 1-06 is secured to the plate 46many SuitabIeMmanner'and is provided With-a-depending par-tel threadedlyengaging the hand .screw 90. .I-n.order tolshift the seat plate. 92,. astheshand screw isthreaded in or out with respect to the part "18, thehand screw carries suitable abutments or. stops which engage alug H0secured .toithe. seat plate 92 as by screws I I2. In the, formishown,such stops include washers H4 andl [6 together withcotter pins H8 andI20, although it will be understood that any suitable type of stop maybe used for the purpose of sliding the seat plate 92 with respect tothe. plate 46 as the hand screw 90 is adjusted.

.From. the foregoing, it will be understoodthat to adapt the chairtozanyparticular .person, it is only necessary that the .person sit inthe chair whereupon the depth ofthe seat and the vertical position ofthe back rest may be readily adjusted to the most comfortable positions.For example the first named adjustment may be secured by rotating thehand screw 98 in order to shift the seat plate 92 forwardly orrearwardly with respect to the plate 46 to correspondingly increase ordecrease the depth of the seat. During such operation, the hand screw 6%is threaded into or out of the bracket 5&5 and the seat plate 92 isshifted through the cooperation between the stop washers H4 and H6 andthe lug Hi3. When the seat shifts, the enclosed guides formed by theparts 94, 8'6 and 32 on the one hand and parts 85, 33 and 1M on theother slide along the opposite edges of the plate 58.

Following these initial adjustments, it is only necessary to adjust thetension of springs ill and 52 by operation of the hand wheel 18 in orderto obtain the desired resistance to tilting of the back. It is herenoted that due to the shape of the cam slots 54 with which the camrollers 56 and 58 cooperate, the back lfi is normally maintained in anupright or posture position with a predetermined force which must beovercome by a predetermined pressure against the back rest beforetilting of the back occurs. This will be clear when it is seen that thecontour of the slot 54 at I22 is extended toward the left beneath thecam roller, see Fig. l, and hence an appreciable force must be exertedbefore the cam rollers 56 and 58 may be moved from the upper ends of thecam slots l, during forward pivoting of the adjusting member 32. Ifdesired the contour at I22 may be so shaped as to provide an increasedresistance before tilting action of the back may be secured, it beingonly necessary to curve the cam slots further to the left beneath thecam rollers at I22 as seen in Fig. 4.

In operation, the parts occupy the normal, upright or posture positionillustrated in Figs. 1, 3 and l. Should the occupant exert thepredetermined pressure sufficient to overcome the tension of springs 79and E2, the back it may be tilted to the full line position shown inFig. 2 whereupon the seat i l will be shifted forwardly as heretoforepointed out, such action being secured through the association of theadjusting member 32 with the cam rollers 58 and 55 carried by arms 22and 2-4 of the hack and through the connection with the seat It by meansof the brackets 4-8 and 5G and the shaft 52. Due to the concurrentmovements of the back and seat, it will be understood that anexceedingly comfortable action is secured. In particular, it will beseen that as the back is tilted and the upper portion of the occupantsbody moves rearwardly of the pedestal iii, the forward shifting of theseat, carries the lower portion of the occupants body forwardly. Thusthe center of weight will be maintained over the pedestal of the chairand any tendency toward unbalance, by reason of tilting of the back, iseliminated.

There has thus been provided by the present invention, a novel posturechair construction embodying a variety of advantageous features, all ofwhich cooperate to increase the comfort of the occupant. For example,the tiltable back is so arranged with respect to the seat, as toautomatically shift the latter forwardly as the back tilts rearwardly,thereby resulting in an easy, natural action on the part of theoccupant. Such operation moreover increases the stability of the chair,since the center of weight is maintained over the pedestal at all times.A further desirable feature insures the elimination of all back rubduring the tilting action, this being secured by the combined movementsof the back and seat and the pivotal movement of the back rest.

While the invention has been shown and described herein withconsiderable particularity, it will be understood by those skilled inthe art, that various changes and modifications thereof may be resortedto without departing from the spirit of the invention. Reference willtherefore be had to the appended claims for a definition of the limitsof the invention.

What is claimed is:

1. A chair comprising a support, a seat slidably mounted on saidsupport, a back pivotally connected with the support beneath the seat soas to be capable of tilting movement, and means interconnecting the backand seat for moving the latter forwardly with respect to the support asthe back is tilted rearwardly.

2. A chair comprising a supporting pedestal, a seat spider carried bythe upper end of the pedestal and provided with a pair of forwardlyextending arms, a seat slidably mounted on the spider, a back, means forpivotally connecting the back to said arms so as to be capable oftilting movement, and means interconnecting the back and seat for movingthe latter forwardly with respect to the spider as the back is tiltedrearwardly.

3. A chair comprising a support, a seat slidably mounted on saidsupport, a back pivotally connected with the support beneath the seat soas to be capable of tilting movement, an operative connection betweenthe back and seat for moving the latter forwardly with respect to thesupportas the back is tilted rearwardly, and resilient means beneath theseat for normally maintaining the back in normal upright position andyieldingly resisting the tilting movement thereof.

4. A chair comprising a supporting pedestal, a seat spider carried bythe upper end of the pedestal and provided with a pair of forwardlyextending arms, a seat slidably mounted on the spider, a back, means forpivotally connecting the back to said arms at the forward ends thereofso as to be capable of tilting movement, means operatively connectingsaid spider, back and seat for moving the latter forwardly with respectto the spider as the back is tilted rearwardly, and resilient meansbeneath the seat for normally maintaining the back in normal uprightposition and yieldingly resisting the tilting movement thereof.

5. A chair comprising a support, a seat slidably mounted on saidsupport, a back pivotally connected with the support beneath the seat soas to be capable of tilting movement, and means including an adjustingmember pivotally connected with the support and the seat and operativelyconnected with the back for movingthe seat forwardly with respect to thesupport as the back is tilted rearwardly.

6. A chair comprising a supporting pedestal, a seat spider carried bythe upper end of the pedestal and provided with a pair of forwardlyextending arms, and a pair of rearwardly extending arms, a seat slidablymounted on the spider, a back, means for pivotally connecting the backto the forwardly extending arms so as to be capable of tilting movement,and means including an adjusting member pivotally connected with saidrearwardly extending arms and the seat and operatively connected withthe back for moving the seat forwardly with respect to the support asthe back is tilted rearwardly.

'l. A chair comprising a supporting pedestal, a sea'tspider carried bythe upper end of the pedesannual taland provided. with a pair offorwardlyextending arms,v and a. pair of rearwardly-extending arms, aseatslidably mounted 'onthespider, a back having a substantially uprightpart at the rear of the seat and a pair of arms positioned be.- neaththe seat, means for pivotally connecting the back to the forwardlyextending arms so that the back'is capable of tilting movement, anadjusting member pivotally connected with said rearwardly extendingarms, means for pivotally connectingsaid adjusting member and seat, andmeans-carried by said back arms and operatively connected with saidadjusting member for moving the latter about the first named pivotalconnection tolmove the seat forwardly as the back is tilted rearwardlv;

8. A chair as defined in claim 7 including in addition, resilient meansinterposed between the adjusting member and said forwardly extendingarms for normally maintaining the back in normovement, a seat positionedabove said spider,

means including a pair of rollers carried by opposite ends of said shaftfor supporting the seat for slidable movement with respect to thespider, and .means pivotally connected with said .spider and operativelyconnected with theseat andthe' arms of the back formoving the seatforwardly with respect to the spider as the back istilted rearwardly. v

10. A chair. comprising a supporting. pedestal, a seat spider carried bythe upper end of the pedestal and provided. with apair of forwardlyextending arms, a back having anuprightpart and a pair of arms arrangedsubstantially parallel to the first named arms, means including a shaftpivotally connecting the forward ends ofall of said arms so that theback is capable-10f tilting movement, a seat positioned above saidspider, means including a pair of rollers carried'by opposite ends ofsaid shaft for supportingtheseat for slidable movement with respect tothe spider; means for sliding the seat forwardly with respect to thespider upon rearward tilting movement-of the back, and resilient meansbeneath the seat for normally maintaining the back in normal upright.position and yieldingly resisting the tiltingmovement thereof. 2

11. .A chair comprising a supporting pedestal, a 'seat spider carried bythe upper :end of the pedestal and provided with a pair of forwardlyextending arms, a back having an. upright part and a pair ofarmsarranged substantiallyxparallel to the first named arms,means-including a. shaft pivotally connecting the forward ends of allrofsaid-arms so that the .back is capable of. tilting movement, a seatpositioned abovesaid spider, means including a pair of rollers carriedby-opposite ends of said shaft for supporting-the seat for slidablemovement with respect tothe spider, an adjusting member pivotallyconnectedlwith said spider, means for pivotally connecting saidadjusting member and seat,-and means carried by the arms of the back andoperatively connected with said adjusting member for. moving the'latterabout the first named pivotal connectionto. move the seatforwardly astheback istilted rearwardly;

12. A.:chair comprising a supporting pedestal, alseat spider carried bythe upper end of the pedestal =and provided with a pair of forwardlyextendingarms, a seat slidably mounted on the spider, aback, means forpivotally connecting the back-tosaid arms so as to be capable of tiltingmovement, .and means for moving the seat forwardly with respect to thespider as the back is tilted, rearwardly, said means including a platepivotally connected with said spider, means pivotally connecting saidplate to the seat, and means interconnecting the back and plate to movetheplate about the first pivotal connection.

13. A chair comprising a supporting pedestal, a seat spider carried bythe upper end of the pedestal and providedwith a pair of forwardlyextending arms, a. seat slidably mounted on the spidena back, means forpivotally connecting the back to said arms so as to be capable oftilting movement, and means for moving the seat forwardly with respectto the spider as the back is tilted 'rearwardly, said means including anadjusting. member having a pair of spaced-apart paralleLplateseachformed with a cam slot, meansxfor pivotallyconnecting said plates withsaid; spider and seat at spaced apart points, and a-pair of cam rollerscarried by said back and positioned withinsaid cam slots.

14. Archair comprising a support, a substantially horizontalplateslidably mounted on the support, a seatnslidably mounted on the plate, abackzzpivotally connected with the support beneath"the-,plate so-as tobe capable of tilting movement,ymeans interconnecting the back,supportzandxplate for-moving the plate and seat mountedzthereonforwardly with respect to the support -asfithelback istilted rearwardly,and means for initially slidably adjusting. the position of: the-"seatwith respectto the plate.

l5. Azo'hair; comprising asupport, a substantially. horizontalrplateslidablymounted on the support, a :seat slidably mounted on the plate, aback pivotally connected with the support beneath'the plate-so as to becapable of tilting movement, means interconnecting, the back, supportand plate'for moving the, plate and seat mounted thereoniforwardly. withrespect to the support as the:.back isi tilted rearwardly, and meanscomprisingzcooperating threaded members carried by said "seat andv platerespectively for initially adjusting. the position of the seat withrespect to the plate.

. l6...A:; chair. comprising a supporting pedestal, a..zseat..'spider:carried by the upper end of the pedestaland provided with a pair offorwardly exten'd'mgrarms, a seatxslidably mounted on the spitier, a::back', :means' for pivotally connecting the back to said .arms so as.to be capable of tilting movemenhandmeans for moving the seatforwardly/withrespect to the spider as the back is tiltedyrearwardly,saidv means including an adjusting member having a substantiallyvertically arranged :curved. cam slot, and a cam member carried by theback and cooperating with said slot.

- .17 A-Echair comprising a support having a seat mounted. thereon forsliding movement with respect;thereto,,a back for the chair, means forpivotallyuconnecting the back with the support so thattjhe back may tiltrearwardly with respect to theseat, resilient means normally acting tomaintainlthe/rback in an upright position. and yieldinglyn-jresistingtilting movement thereof, a part pivotally-connected-with the supportand the seat, andimeans including-a connection between said 9 10 backand said part for moving the latter about REFER]; E D the pivotalconnection with the support to slide No S CITE the seat forwardly withrespect to the support as The f01 1W1ng references are of Taco! d in thethe back tilts rearwardly. me of thls patent? 18. A chair as set forthin claim 17 wherein 5 UNITED STATES PATENTS said connection includes acam slot formed in said part and a member carried by the back and re-Number Name Date ceived in the slot June 19. A chair as set forth inclaim 18 wherein the 798032 Gllson 1905 2,257,583 Wood Sept. 30 1941reslllent means is positioned between the support 10 I and said part2,420,745 Harmon May 20, 1947 ROY A. CRAMER.

